The
Ermine has a very elongated slender body
with short legs and a medium length tail.
Body length ranges from 17-24 cm. The
coat is brown and white with prominent
black from tip to tail. The coat changes
color in winter.

M. erminea is primarily noctural
with a diet consisting of small rodents,
birds, eggs, frogs and insects. The short-tailed
weasel is swift, agile and has a keen
sense of hearing and smell.

Adult males are dominant over females
and young. Females are polyestrous but
produce only one litter per year. Mating
generally occurs in late spring or early
summer. Litter size averages 6 young.